Dinâmica de populações e pesca do tubarão-martelo Sphyrna lewini (Griffith &amp; Smith, 1834), capturado no mar territorial e zona econômica exclusiva do sudeste-sul do Brasil

Kotas, Jorge Eduardo; Júnior, Miguel Petrere

doi:10.11606/t.18.2004.tde-08122015-105215

Cited by 18 publications

(46 citation statements)

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“…Schwartz (1983), with whole vertebrae in the eastern USA coast and Andrade and Mazzoleni (1999) with vertebrae cuts from southern Brazilian scalloped hammerheads also obtained evidence of annual ring formation. The birth ring appears in pups during the spring-summer season, a reproductive period previously described by other authors (Vooren and Klippel, 2005;Kotas, 2004). Birth rings are formed as a response of the stress caused by changing placental viviparity to free-living lifestyle.…”

Section: Discussionmentioning

confidence: 66%

“…Marginal increments were significantly different among months (Kruskal-Wallis c 2 = 18.6; p = 0.017). However, in a previous study carried out by Kotas (2004) who compared the percentual of opaque and hyaline bands found per month, ageing the whole vertebrae of Sphyrna lewini (n = 361), the highest frequency of hyaline bands was observed in winter (Table 2). Also the same author applying marginal increment analysis (MIA) to 260 vertebrae samples, found lower values in winter.…”

Section: Resultsmentioning

confidence: 91%

“…Scalloped hammerheads, Sphyrna lewini, were sampled (n = 245) from landings between 1995 and 2002 (Kotas, 2004) in Ubatuba (São Paulo state) and Itajaí (Santa Catarina state). Fishing in these regions was conducted with surface and bottom gillnetters, surface longliners and bottom trawlers (pair and double-rig).…”

Section: Methodsmentioning

confidence: 99%

“…Shark total length (TL) and the distance between the first dorsal insertion and the precaudal pit (DC) were measured. This later measurement was used, during harbour sampling, to transform shark carcasses in total length (TL), using the following morphometric relationship: TL = 9.125 + 2.7 (DC) (Kotas, 2004).…”

Section: Methodsmentioning

confidence: 99%

“…In developing theoretical growth models, an arbitrary birth date of 1 January, the approximate mid-point of the time-period when neonates were present in the field were adopted (Kotas, 2004). It was also considered that the birth mark is the band associated with a pronounced change in angle in the intermedialia, and that the translucent bands that represent winter growth form approximately one year later.…”

Section: Methodsmentioning

confidence: 99%

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Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Kotas¹,

Mastrochirico

Petrere

2011

Braz. J. Biol.

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Age and growth studies for the scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834) caught along the southern Brazilian coast, were based on ring measurements of vertebrae sections of 115 males, 116 females and 14 unknown sexed sharks between 48 and 344 cm total length (TL). The von Bertalanffy growth models were best fit using back-calculated data. The growth parameters obtained for males, were L ∞ = 266 cm; K = 0.05/year; L 0 = 47 cm. For females, L ∞ = 300 cm; K = 0.05/year; L 0 = 51 cm. An adult female reached 217 cm TL and was 31.5 years old. On the other hand, an adult male was 29.5 years old and measured 234 cm TL. Longevity estimate for males and females was 55 years. Therefore, S. lewini is a long-lived fish. Ageing precision, based on the IAPE index, was 5.6%. Marginal Increment analysis based on MIR index from hammerheads smaller than 105 cm, compared with the percentual of opaque and hyaline bands found per month ageing whole vertebrae, showed an annual ring formation, i.e., in winter.Keywords: elasmobranchs, fisheries biology, conservation.Idade e crescimento do tubarão-martelo-entalhado, Sphyrna lewini (Griffith and Smith, 1834), da costa sul do Brasil ResumoO estudo da idade e do crescimento do tubarão-martelo-entalhado, Sphyrna lewini (Griffith and Smith, 1834), na costa sul do Brasil, baseou-se na leitura de anéis em seções de vértebras de 115 machos, 116 fêmeas e de 14 exemplares com sexo indeterminado, com comprimentos totais (CT) entre 48 e 344 cm. Modelos de crescimento de von Bertalanffy foram mais bem ajustados aos dados de idade e comprimento retrocalculados, considerando sexos em separado. Os parâmetros de crescimento obtidos para os machos foram L ∞ = 266 cm; K = 0,05/ano; L 0 = 47 cm. Para as fêmeas L ∞ = 300 cm; K = 0,05/ano; L 0 = 51 cm. Uma fêmea adulta atingiu um CT de 217 cm e uma idade de 31,5 anos. Por sua vez, um macho adulto tinha 29,5 anos e CT de 234 cm. A estimativa de longevidade para machos e fêmeas foi de 55 anos. O índice de erro percentual médio (IAPE), que avalia a precisão na leitura de idades, foi de 5,6%. A análise do incremento marginal baseada no índice MIR e aplicada em tubarões com CT < 105 cm, comparada com o percentual de bandas opacas e hialinas mensais, obtido através de leituras de vértebras inteiras, indicou um padrão anual na formação dos anéis, ou seja, anéis de inverno.Palavras-chave: elasmobrânquios, biologia pesqueira, conservação.

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Section: Discussionmentioning

confidence: 66%

Section: Resultsmentioning

confidence: 91%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Kotas¹,

Mastrochirico

Petrere

2011

Braz. J. Biol.

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Occurrence, distribution and threats to mobulid rays in Brazil: A review and updated database

Bucair,

Mendonça,

Santos

et al. 2024

Aquatic Conservation

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Mobulid rays are medium‐ to large‐sized pelagic‐dwelling planktivorous elasmobranchs that are circumglobally distributed. Brazil has a high diversity of Mobula species, with five of the nine globally valid species and one additional putative new species. Brazil represents a substantial knowledge gap concerning the ecology, distribution and threats to mobulid rays. In global distribution analyses, several species have been underrepresented along the Brazilian coast. The dataset is composed of information from peer‐reviewed and grey literature, as well as data from scientific expeditions, citizen science collaboration, social media and local news. We found 6,450 records of manta and devil rays along the Brazilian coast, including Mobula tarapacana, Mobula mobular, Mobula thurstoni, Mobula hypostoma, Mobula birostris and the putative new species (Mobula cf. birostris). Our results revealed alarmingly high captures, such as 4.5 tons of M. hypostoma in a single fishery cruise and 809 individuals of Mobula spp. from a single fleet during one year in the Southeastern region. These findings evidence the fisheries' threats to mobulid species in Brazil and highlight previously unnoted species records, such as the occurrence of M. hypostoma on the entire Brazilian continental shelf, including estuaries and M. tarapacana in coastal regions. Integrative information on the occurrence, distribution, and threats to mobulid rays on local and global scales is crucial to supporting strategies for their effective management and conservation.

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Sightings of the endangered scalloped hammerhead shark (Sphyrna lewini) in a coastal no‐take marine protected area in southeastern Brazil

Meira,

López,

Falsarella

et al. 2024

Aquatic Conservation

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Dinâmica de populações e pesca do tubarão-martelo Sphyrna lewini (Griffith & Smith, 1834), capturado no mar territorial e zona econômica exclusiva do sudeste-sul do Brasil

Cited by 18 publications

References 0 publications

Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Occurrence, distribution and threats to mobulid rays in Brazil: A review and updated database

Sightings of the endangered scalloped hammerhead shark (Sphyrna lewini) in a coastal no‐take marine protected area in southeastern Brazil

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